#!/usr/bin/env python

# python-exiv2 - Python interface to libexiv2
# http://github.com/jim-easterbrook/python-exiv2
# Copyright (C) 2021  Jim Easterbrook  jim@jim-easterbrook.me.uk
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Sample program to format exif data in various external formats.

import sys

import exiv2


def syntax(argv, formats):
    print("Usage: {} file format".format(argv[0]))
    print("formats: {}".format(' | '.join(formats)))


def formatJSON(exifData):
    count = 0
    length = exifData.count()
    print('{')
    for datum in exifData:
        count += 1
        print('  "{}":"{}"{}'.format(
            datum.key(), str(datum.value()).replace('"', r'\"'),
            ('',',')[count != length]))
    print('}')


def formatXML(exifData):
    count = 0
    length = exifData.count()
    print('<exif>')
    for datum in exifData:
        count += 1
        print('  <{key}>{value}<{key}/>'.format(
            key=datum.key(),
            value=str(datum.value()).replace('<', '&lt;').replace('>', '&gt')))
    print('</exif>')


def main():
    try:
        exiv2.XmpParser.initialize()

        formats = {
            "json": formatJSON,
            "xml": formatXML,
            }

        if len(sys.argv) != 3:
            syntax(sys.argv, formats)
            return 1;
        file = sys.argv[1]
        format_ = sys.argv[2]

        if format_ not in formats:
            print("Unrecognised format {}".format(format_))
            syntax(sys.argv, formats)
            return 2;

        image = exiv2.ImageFactory.open(file)
        image.readMetadata()
        exifData = image.exifData()

        formats[format_](exifData)

        return 0
    except exiv2.AnyError as e:
        print('*** error exiv2 exception "{}" ***'.format(str(e)))
        return 4;
    except Exception as e:
        print('*** error exception "{}" ***'.format(str(e)))
        return 5;
    finally:
        exiv2.XmpParser.terminate()
    return 0

if __name__ == "__main__":
    sys.exit(main())
